Windows Update is a tool built into Microsoft Windows, to easily allow users to update and patch their versions of Windows. As with virtually all software, bugs and security holes in Windows are being discovered all the time. The Blaster worm which infected computers the world over exploited a security hole which was actually patched on July 16th 2003, almost a month before the worm appeared. This means that anyone regularly running Windows Update would have been immune from the worm before the worm was actually released.

The Bugbear worm discovered in late September 2002 also affected a large number of users, and that exploited a hole that was patched in March 2001! Just like regular maintenance on your vehicle, running Windows Update every couple of weeks can help prevent problems from developing on your system.

To access Windows Update, you will need to be running Internet Explorer 5 or later. If you are running Windows ME, 2000 or XP, you will already have Internet Explorer 5 or 6. If you are running Windows 95 or 98, you may be running an earlier version of Internet Explorer. Please check and install the appropriate version of Internet Explorer first to continue.

To start Windows Update, connect to the internet. Then click on the Start menu, and choose Windows Update. You can also access it by clicking on the Tools menu in Internet Explorer, and then selecting Windows Update. Or you can simply enter http://windowsupdate.microsoft.com/ into the address bar in Internet Explorer.

Whichever method you choose, you will be taken to the Windows Update website. If you are having trouble viewing the site, make sure your Security settings are set to Default (click Tools, Internet Options, Security, Default level). Once there, Windows Update will check to make sure your computer is running the most recent version of the Windows Update Control Software. If not, a window will pop up asking you to install the latest version; choose yes. Once the latest version of the control software is installed, select "Scan for updates". Windows Update will then check your system to work out what updates are available.

This may take a few minutes, and Internet Explorer may appear to have hung; be patient.

The updates are divided into three categories - Critical Updates and Service Packs, Windows XP (or whichever version of Windows you are running) and Driver Updates.

If there are any Critical Updates available they will be automatically selected. If not, you can select the other updates by choosing the category from the list on the left, and then clicking the "Add" button for the updates you want to install. It is strongly recommended that you install ALL Critical Updates and Driver Updates. The other Windows Updates may provide new or enhanced Windows applications and add-ons such as foreign language support, DirectX, Windows Media Player, and so on; these updates are optional, not critical.

Once updates have been selected (either manually or automatically), click on Review and Install Updates to display a list of the selected updates. Sometimes, an update will need to be installed separately from other updates. If this is the case, use the Remove button to remove this update, or to remove all the other updates. Also note the size of the download and the estimated time it will take to download. If there are a lot of updates to download, it may take several hours. Please be aware that some updates (including Internet Explorer 6 and DirectX) download a relatively small control package, which will then attempt to download a large number of other files. The size of these other files are not included in the initial estimate of the size of the download. Usually these updates will require separate installation anyway. Of course, downloading the updates will take up your as much of your bandwidth as it can, which means that all other browsing, email, and other internet applications will run very slowly.

When you have selected the updates to install, click on the Install Now button. A Licence Agreement window will pop up, which you must accept to proceed. Once you click Accept, your updates will begin to download.

Once the updates have been downloaded, they will automatically install themselves (this may take several minutes). Usually you will then be prompted to restart your computer. Once this has occurred, the selected updates will have been installed on your computer. You should run Windows Update again, until there are no more Critical Updates to install, and you have all the other updates you want. You should then check for updates every couple of weeks.